Ratchet relay with articulated driving mechanism



June 16, 1964 w. w. WRIGHT 3,137,176

RATCHET RELAY WITH ARTICULATED DRIVING MECHANISM ATTORNEYS.

June 16, 1964 w. w WRIGHT 3,137,176

RATCHET RELAY WITH ARTICULATED DRIVING MECHANISM 'Filed Feb. 12 1962 2 Sheets-Sheet 2 \%5 x22 I48 40 M8 r// /0 A 92 I 1 ///l &.

1N VEN TOR.

ATTORNEYS.

United States Patent Ofiice 3,137,176 RATCHET RELAY WITH ARTICULATED DRIVING MECHANISM William Warren Wright, Wheaten, Ill., assignor to Guardian Electric Manufacturing Co., Chicago, Ill., a corporation of Iilinois Filed Feb. 12, 1962, Ser. No. 172,455 13 Claims. (Cl. 74-142) This invention relates in general to a ratchet relay or rotary stepping switch and more particularly relates to an improved pawl and detent arrangement for driving a rotatable member through a specific are or step and for preventing backlash and over travel.

In the usual stepping switch arrangement, a ratchet member must be driven through a specific increment or are in response to each energization or deenergization of a coil or other actuator. This enables the ratchet member to control a respective electrical circuit in each of a plurality of different positions. The actual circuit is completed either by a spring wiper or by cam controlled springs, but, in order for the position of the wiper or cam to be repetitively set with accuracy, the ratchet must both be moved through a specific increment or step and it must be adequately held in the position to which it is moved.

A pawl carried by a pivotable armature is provided to engage'with the ratchet teeth for driving the ratchet. The armature of course pivots in response to energization of the coil for bringing the pawl into engagement with the ratchet. The step through which the ratchet is moved by the pawl is determined by where a detent engages either the pawl or a tooth ofthe ratchet during their movement. This detent must absorb the driving force of the pawl and the momentum of the ratchet. Another detent is usually provided for then holding the ratchet in its moved position so that the armature and pawl can be retracted without disturbing the ratchet position.

Actually the sequence of movement is 'quite complex and requires exceedingly fine adjustment. The armature describes a rotary movement about one axis and the ratchet arotary movement about a second axis displaced from the first axis. These rotary movements control the manner in which the armature thrust can be applied to the ratchet'and it'is therefore necessary to pivot the pawl on the armature to enable the driving engagement with the ratchet to be maintained. The pawl is therefore also spring biased so that it will return to normal on retraction of the armature. The spring is usually small and difficult to assemble and if subject to large flexure movements, its life may be quite short.

For terminating the ratchet movement at the proper position, one detentrnust stop the ratchet after it has been thrust forward a specific increment by the pawl. This detent must therefore be carefully adjusted to engage either the pawl at a specific position or is pivotally mounted on the armature so that it swings with the pawl in an are which intercepts the ratchet at a specific point in the ratchet travel. y

.As pointed out, when the pawl is retracted toits normal position on release of the armature, the ratchet must be held stationary despite any forces transmitted thereto duringthe retraction. The other detent, which is provided for this purpose, is usually a flat spring, and

in some constructions it may actually be one of the circuit members controlled by the cam or the ratchet. This spring lifts to allow a ratchet tooth to be rotated in one direction by thepawl and then falls into a position corresponding to a recess between the ratchetteeth. If the ratchet should now tend to rotate in the reverse direction Patented June 16, 1964 as the pawl is retracted, the transverse side of the spring Will be engaged and instead of lifting, it will act as a stop;

This type of arrangement, however, requires that the spring be very carefully adjusted with respect to the desired ratchet position and also to insure that it does not become misaligned.

As may readily be understood, the tolerances of the various parts are quite critical and careful and often repetitive adjustment is needed when assembling the same. In addition, since the forces are usually applied to the same tooth face, wear is a serious problem as it can resuit in misalignment of the various parts and in those cases where the detent is arranged to act against the pawl, the pawl is locked between a ratchet tooth and the overtravel detent. It may then be held in the operated posi-' tion instead of being retracted after the end of the operational armature stroke sothat the mechanism is rendered completely inoperative.

g It is, therefore, an object of the present invention to provide an improved pawl and detent construction for rotating a ratchet member through a predetermined arc.

. It is a further object of this invention to provide an improved pawl and detent construction for use in a rotary switch.

It isanother object of this invention to provide an improved detent arrangement for holding a ratchet member in the position to which it is moved by a pawl, while the pawl is retracted from engagement with the ratchet.

It is a further object of this invention to provide an improved detent arrangement for absorbing the rotational inertia of a ratchet member and terminating movement of the ratchet member at a specific position. i

It is still a further object of this invention to provide a pawl and detent assembly which is extremely simple It is also an object of the present invention to provide a ratchet which is detented by a helical spring.

'It is still a further object of this invention to provide a detent comprising a helical spring whose'periphery intersects the periphery of a ratchet member so that the helical spring acts as a detent.

bly embodying the principles of the present invention;

-FIGURE- 2 is a top elevational view of the switch assembly shown in FIGURE 1;

FIGURE 3 is a sectional view taken through the line 33 in FIGURE 2;

FIGURE 3a is a sectional view illustratingthe pawl,

detent and ratchet assembly after the pawl has rotated the ratchet through part of a step;

FIGURE 4 is a sectional view showing the pawl, detent and ratchet assembly after the ratchet has been moved through a complete step;

FIGURE 5 is a sectional view taken through the line 5-5 of FIGURE 3;

FIGURE 6 is an end elevational view of the ratchet taken through the line 66 of FIGURE 5;

FIGURE 7 is an exploded perspective view of the ratchet and cam assembly;

FIGURE 8 is an exploded perspective view of the detent and armature assembly;

FIGURE 8a is a sectional view illustrating the manner in which the pawl and detent are assembled to the armature; and

FIGURE 9 is a side elevational view of the switch assembly, illustrating the manner in which one of the detent springs may be simply transposed to allow the armature to operate the ratchet, with the armature being actuatedly moved in a direction opposite to that normally used.

In the drawings the ratchet relay assembly is generally indicated by the reference character 111. It includes a coil and heel piece assembly 12. The assembly 12 comprises a coil 14 wound on a bobbin or spool 16 and having a core 18 extending therethrough. The upper end of the core is split and a ring 19 having a crossarm 20 is press fitted to the split end of the core. The other end of the core is mounted on a heelpiece 22 in a conventional manner.

The heelpiece 22 comprises an L-shaped member of magnetic iron having an elongate horizontal arm 24 and a vertical arm 26. The core 18 is connected to the arm 24 so that the coil 14 is adjacent arm 26. Top and bottom end flanges 28 are provided on the bobbin with the bottom flange abutting the arm 24. The bottom flange 28 instead of being constructed in the conventional circular configuration is provided with a projecting arm 29 on one side and a pair of terminal lugs 34) are embedded in one end of arm 29 as best seen in FIGURES 2 and 3. A generally triangular horizontal recess 32 terminating in a slot 34 through the top wall of arm 29 and along one edge of recess 32 is provided in arm 29 for the purpose of enabling leads to be easily extended from the lugs 39 to opposite ends of the coil with minimum danger of damage to the leads.

A horizontal flange 34a extends laterally from arm 24 adjacent its short axis in a direction opposite arm 29 as best seen in FIGURES l and 2. The flange 34a has a mounting hole 35 and it or other apertures may be used to mount the assembly 10. An upstanding L-shaped arm 36 is provided at the end of flange 34a for mounting a spring pile-up assembly 38.

The assembly 38 comprises a spring 40 carrying a pair of contacts 42 and 44 on respective sides and adjacent one end, which end terminates in a loop 46. The contacts 42 and 44 are adapted to engage respective contacts 48 and 50 carried by respective flat springs 52 and 54. The springs 40, 52 and 54 with insulators 56 therebetween and spring stitfeners 57 for springs 52 and 54 are all mounted on arm 36 by means of the screws 58 so that the springs project in a direction parallel to arm 24 and spaced above and to one side thereof. Lugs 59 on the respective springs are provided for the purpose of extending electrical connections thereto.

A pair of upstanding apertured ears or flanges 6d and 61 are formed along opposite edges of arm 24 adjacent its right end as seen in FIGURES 1 and 2. A hook member 62 is provided on each ear and a coil spring 64 is mounted therebetween. A shaft 66 having a hexagonal head 68 as best seen in FIGURES 5 and 7 is inserted through the apertured ears and 61. The shaft 66 carries a nylon cam 70 adjacent the head 68 and the side of the cam has a correspondingly shaped recess to receive the head in interlocking relation so that the cam and shaft may rotate together. The cam periphery is provided with spaced apart teeth 72, each having a shallow recess '74 in its top wall and a deep wide recess 76 is defined between the teeth. The walls of the recesses '74 and 76 are adapted to engage the loop 46 on spring 411 for controlling the position of the spring by flexing it upward when engaged in recess '74 and enabling it to flex downward when engaged in recess 7 6.

The cam "70 has hollow shaft '76 formed integral there with and which surrounds shaft 66 and both shafts extend through the ear 6%. The shaft 78 is provided with a shoulder 35), and a semi-flat face portion 82 adjacent the end of the shaft, and the face portion 82 is received within .a semi-rectangular shaped aperture 84 formed in a nylon ratchet member 86 to prevent relative rotation between the cam 7 t and ratchet member 86.

When the ratcheting structure is assembled in operative position, the ratchet member 86 is located between cars 60 and 61. The ratchet member has a hub portion 88 extending therefrom and is adapted to be mounted on shaft 66. The hub 83 is provided with a shoulder 90 for engagement in the ear 61, while the end of shaft 66 protrudes through the ear. A nylon washer 22 together with a retainer ring 94 are assembled on the end of shaft 66 to prevent separation of the components.

The periphery of ratchet member 86 is provided with a plurmity of spaced apart teeth fi6, each having a root 98, and a lip or overhang formed above the root and on the front face of each tooth, as best seen in FIGURES 3, 4, 4a, 6 and 7. The back wall of each tooth is formed by a pair of intersecting flat faces 1&2 and 104 with face 1112 forming a juncture edge with the lip 190. The teeth 96 are engaged by the coil spring 64 normally resting between the teeth, and by a pawl and detent assembly 106.

The pawl and detent assembly 106 comprises a U-shaped member 108 as best seen in FIGURE 8. The member 108 is mounted on one end of an armature or activating member 110, as best seen in FIGURES 1-4. The other end of armature 110 is pivotally mounted on an edge face 112 at the upper end of the heelpiece arm 26 so that it lies above and is aligned with the core 18 of the coil and heelpiece assembly 12. A coil spring 114 is connected to and mounted between a tang or tine 116 on the arm 26 and a tine 118 on armature 110 so as to bias the armature 110 away from the core 18. A stop member 120 formed on the arm 26 and protruding through a suitable aperture in armature 110 is bent over to limit or control the spacing between the core 18 and armature 110 when the coil 14 is deenergized.

The U-shaped member 108 comprises a bifurcated base leg 122, a pawl leg 124 and a detent leg 126. A short guide member 127 depends from between the bifurcations or arms 128 of leg 122. The pawl leg has a flat end 129 adapted to engage a root 98 of each ratchet tooth beneath the lip 100. A recess 130 is provided at the upper end of the pawl leg 124 between the bent over portion of arms 128.

To assemble the member 108 to the armature 110, the detent leg 126 is inserted through a widened portion 134 of an aperture 136 adjacent the free armature end, as indicated in FIGURE 8a. The detent leg 126 has a narrow neck portion 138 which is then moved into the narrow portion of aperture 136 in straddling relation, so that shoulders 140, adjacent the neck, will act as, a stop during movement in an upward direction. The guide member 127 is in the meantime slid or moved past a tongue 141 on the armature end and a tongue 142 protruding into aperture 136, until member 127 drops into the widened portion 134 of aperture 136. The tongues 141 and 142 are given a slight deformation from the horizontal during formation of the armature so that a top wall 144 on the pawl leg 124 can be moved beneath the tongue 141 during assembly. The member 103 is moved back until edge faces 146 on the end of the armature abut the bent over portions of arms 128 to form pivot edges or faces therefor. The guide member 127 is then engaged in the portion 134 of aperture 136, just past tongue 142.

Thereafter the deformation in tongue 141 is straightened by moving it in the direction indicated by the arrow 147 in FIGURE 8a sothat member 108 cannot be disassembled from the armature without again deforming tongue 141, in the opposite direction. Thus the member 108 can be moved only a short distanceto the right as the member 127 then engages tongue 142, nor can member 127 be lifted out of aperture 136, since with the deformation straightened, the top wall 144 on leg 124 is now prevented from moving upward. Thus the member 108 is limited to simple pivotal movement about edge faces 146 on the free end of the armature with the shoulders 140 and the guide 127 controlling the path and limits of rotation of said member 108. I

Respective legs 148 of a fiat spring 150 are received beneath the arms 128 on member108. The spring 150 serves to bias the pawl leg 124 in one direction about the pivot edges 146 so that the shoulders 140 on the detent leg 126 are abutting the underside of the armature. Since the legs 148 engage the member 108 close to the pivot faces 146, the spring is subject to minimal flexure.

It will be noted that the spacing between the pawl leg 124 and the detent leg 126 is slightly more than the distance of a radial line from the axis of shaft 66 to the periphery of the teeth 96 and that pawl leg 124 points inward toward the space between the teeth 96 due to the bias imparted by spring 150. The spacing between pawl leg 124 and the detent leg 126 will vary, depending upon the ratchet design. In the design as shown in the drawings, the spacing is about two-thirds of the diameter,

of the ratchet, and the spacing is always greater than the radius of the ratchet.

It is only necessary that the pawl face 129 contact the ratchet 86 at some time during the armature stroke, which will leave enough travel of the pawl 124 for causing the ratchet to be rotated through a predetermined are. This,

may be done in a simple manner by bending the armature until the clearance between it and the core is sufficient to enable detent leg 124 to engage the ratchet. De-

- tent leg 124 engages the ratchet and drives it through the I required rotation, and said detent leg engages the back of the tooth to stop forward rotation and absorbs the rotational inertia. It will also be noted that the armature adjustment awayfrorn the core is only critical insofar as furnishing sufiicient power to operate the mecha-..

nism. Therefore, no critical adjustment problems are encountered in securing proper engagement between the pawl and the ratchet teeth. By providing a large clearance between the lip 100 on one tooth and the surface 102 on an adjacent tooth, the problem of where the free leg 124 pivots against the bias of spring 150 as the armature moves down, the detent leg 126 moves into a position where the fiat face 102 of a tooth moving in a direction opposite that of a tooth driven by pawl 124 can engage against the detent. Thus all the momentum of the movement will be received along the longitudinal axis of the detent leg and transverse to its major dimension. In addition, the problem of where. the detent leg engages the ratchet is minimized since itv can engage anywhere along the flat face 102.

, The spring 150 is provided with an L-shaped depending lip 152 at the end opposite legs 148. The lip 152 is received in a widened portion 154 of an aperture 156 in the armature 110 and engages against the bottom side of the armature. A split portion 158 adjacent one edge of an 162 on the armature.

aperture 160 provided in the spring 150 between the lip 152 and the legs 148 is formed so that it depends slightly. The portion 158 is thus adapted for engagement against a stop 162 on the armature and extending into the aperture 156. This arrangement permits the spring 150 to be simply snapped into place by inserting the lip 152 through the widened portion 154 and then sliding the spring back until portion 158 is snapped into engagement behind stop The spring 150 may be mounted on armature 110, either before or after member 108, and, if mounted subsequent to the assembly of member 108, the legs 148 are simply inserted below leg 122 of member 108, before the spring is snapped into position.

To operate the switch assembly, the coil 14 is energized by an electrical pulse and it creates a magnetic field which attracts the armature 1l0to the core 18. As the armature moves toward the core it moves the pawl leg 124 downwards, as shown by the arrow 164 in FIGURE 3,

. to cause its end 129 of the pawl to engagewith a root portion 98 of a tooth 96a, directly above the horizontal mid plane of the ratchet 86. The spring 150 serves to bias the leg 124 so as to move the end face 129 through the space between the lip 160 on one tooth and the surface 104 on the adjacent tooth.

As the ratchet 8-6 rotates, the back face 102 of the succeedularposition directly above the flat face 102 of a tooth ratchet.

; on the ratchet tooth 96d during the ratchet rotation.

ing tooth 96b engages the pawl leg 124 to pivot it outwards from the axis of the ratchet and about edge faces 146, as indicated by arrow 167 in FIGURE 30. The pawl leg 124 is thus rotated about edge faces 146 until the legs 124 and 126 are substantially perpendicular to the armature, at which time the leg 124 is engaged with a tooth lip 100 as shown in FIGURE 4. 7

As the member 108 pivots about the edge faces 146, the detent leg 126 is brought into a substantially perpendic- 96c just to the right of the vertical mid plane of the ratchet as seen in FIGURE 4. The face 102 on tooth 96c therefore engages the end of the detent leg 126 as the tooth moves upward toward the vertical mid plane of the Thus the ratchet 86 is brought to an immediate and positive. stopas the thrust is directed along theaxis of the leg 126. a

The coil spring 64whose periphery intersects the periphery of the ratchet is urged outward by the face 102 As soon as the lip 1000f that tooth 96d is moved past the spring 64, the spring tends to return to a position between the teeth to prevent any backlash, and over-travel of the ratchet is prevented by the detent pawl 126. Thus the A movement of the ratchet is limited to a specific increment during each step.

On de-energization of the coil the armature is released and it returns to normal under the bias of spring 114. This disengages the member 108 from the ratchet 86 while legs 1480f spring 150 pivot the member 108 into its it is engaged in a deep recess 76, the spring 40 moves under its own tension to establish engagementbetween contacts 42 and 48, but in either event the wall of the loop 46 engaged against the walls of the recess additionally serve to resist displacement of the cam 70 and the ratchet 86.

It is to be noted that prior constructions are such that the detent action would be provided by the spring action on the loop 46 alone. Thus the position in which the ratchet member would be held would depend on where loop 46 engaged the walls of the recesses on cam '70. It would therefore be necessary to shift the loop 46 longitudinally until it engaged the cam 7d at a point that corresponded to a full step and this in turn might require readjustment of the pawl and detent position with respect to the cam.

With the detent spring 64- being urged toward the ratchet axis as each tooth moves it aside, it will immediately tend to return into the recess between the teeth as a tooth passes. Thus it will always re-engage in a recess at a position corresponding to a full ratchet step and without the need for adjustment.

FIGURE 9 illustrates how the ratchet is operated in response to movement in a direction opposite to that described, and adapted for various control operations, such as a clothes washing machine. In this arrangement the coil, core and bobbin may be omitted and the member, which happens to be the armature of the earlier described device, may be adopted to be operated by a device such as a plunger arm 168, which for purpose of illustration is shown extending through an appropriate guide aperture in a support member, here represented as the heelpiece arm 24. For example, this plunger may be actuated manually, mechanically, or electro-mechanically, to provide a desired contact switching sequence. An additional spring 64a, similar to spring 64, is extended between ears 61 and/or 61 and the stop 162; and if desired spring 64 may also be used as a detent for the ratchet '70.

It will be noted that the armature or member 114) is shown in its normal retracted position since spring 64 is effective to bias it downward. This position corresponds to that shown in FIGURE 4 with pawl leg 124 in a perpendicular position and the detent leg 126 engaging the flat face 102 on one of the teeth 96. Thus the ratchet is positively held.

At the appropriate time, the pusher arm 16% is given an upward movement against the tension of spring 64. The detent action may depend on the loop 46 and/or detent spring 64. The arm 164 moves the member illil upward until it corresponds to the position shown in FIGURE 3.

On release of the plunger 168 the spring 64 will move the member lit downward to follow the plunger 168. The pawl leg 124 will therefore rotate the ratchet and the detent log are will control the degree of movement as already explained.

It will be appreciated, of course, that the type of movement just described corresponds to that in which the switch is stepped on de-energization of the coil. Therefore, the present invention is not to be limited to those switches in which stepping occurs on coil energization, nor is it to be limited to devices in which the motive power is supplied by a magnetic field.

Although I have herein shown and described certain preferred embodiments of my invention, manifestly it is capable of modification and rearrangement without departing from the spirit and scope thereof. I do not, therefore, wish to be understood as limiting this invention to the precise embodiments herein disclosed, except as I may be so limited by the appended claims.

I claim: I

1. An improvement for biasing a unitary pawl and detent member which is pivotally carried by an armature, said improvement comprising a fiat spring having an L- shaped depending leg at one end and a pair of legs projecting from the other end, said pair of legs being positioned between said unitary pawl and detent member and said armature, and said flat spring being adapted to bias said pawl and detent member in one direction about its pivotal mounting on said armature, said armature having an opening for receiving said L-shaped leg with one arm of said L-shaped depending leg being adapted to engage the lower surface of said armature, said armature having a stop element projecting into said opening, and a split portion on said spring adapted to engage said stop element upon depression of said split portion, whereby. said spring is held in place on said armature by said L- shaped depending leg engaging said armature and by said split portion engaging said stop element.

2. An improvement for biasing a unitary pawl and detent member which is pivotally mounted on an armature, the improvement comprising a fiat spring engaging one surface of said armature and one surface of said unitary pawl and detent member biasing said unitary pawl and detent member in one direction about its pivotal mounting, means on said spring for engaging the lower surface of said armature, and means on said spring for placing a portion of said spring in tension along one axis when mounted on said armature for preventing separation of said spring from said armature.

3. In combination, a ratchet having spaced apart teeth, an armature pivotally mounted and aligned with said ratchet, said armature having a passageway, a pawl member pivotally carried by said armature, said pawl member having a base portion, a first depending leg' at one end of said base portion for rotating said ratchet and a second depending leg at the other end of the said base portion, said second leg extending into said passageway and being adapted to cooperate with said armature in retaining said pawl member connected to said armature, means for biasing said pawl member in one direction about its pivotal mounting, and means for moving said armature toward said ratchet for engaging said first depending leg of said pawl member between a pair of adjacent teeth onsaid ratchet, whereby said ratchet is rotated in response to the engagement of said first depending leg with said ratchet.

4. A combination for use in rotating a ratchet having a plurality of spaced apart teeth, said combination comprising an armature, a pawl member pivotally carried by said armature, and a flat spring having a pair of legs projecting from one end, said pair or legs being positioned between said pawl member and said armature and being adapted to bias said pawl member in one direction about its pivotal mounting on said armature and being arranged to allow said pawl member to pivot in another direction responsive to said pawl member'engaging and driving said ratchet.

5. For use with a relay comprising a pivotable armature having a free end and a unitary pawl and detent member, having spaced apart, depefnding legs, for rotating a ratchet through a predetermined increment; the improvement comprising an armature having a passageway at its free end for receiving one of the depending legs of said unitary pawl and detent member, said passageway and said one depending leg being in cooperating relationship for assisting in maintaining said unitary member pivotably mounted on said armature, and a tongue projecting from the free end of said armature, the other of said depending legs of said unitary member extending from beneath said tongue and cooperating therewith for also assisting in maintaining said unitary member pivotably mounted on said armature, said other leg engaging and rotating said ratchet through a predetermined increment in response to the pivoting of said armature.

6. For use with a relay comprising a pivotable armature having a free end and a pawl structure having spaced apart, depending legs; the improvement comprising an armature having a first opening at its free end, a first tongue projecting from its free end, said pawl structure straddling the portion of the armature between said first tongue and said first opening, said first tongue and said first opening engaging and cooperating with said depending legs of said pawl structure for pivotably maintaining said pawl structure on said armature, a flat spring member for biasing said pawl structure about its pivotable mounting on said armature, a second opening in said armature spaced from said first opening, and a second tongue projecting into said second opening engaging under tension a portion of said flat spring which is depressed into said second opening.

7. For use with a relay comprising a pivotable armature having a free end and a pawl structure, having depending legs at its opposite ends, for rotating a ratchet having a plurality of spaced apart teeth; the improvement comprising an armature having a pair of pivot faces at its free end, a tongue projecting from between said faces, and a passageway spaced from said faces and in alignment with said tongue, said pawl structure being pivotably seated on said pivot faces, one of the depending legs of said pawl structure extending from beneath said tongue for engaging and rotating said ratchet in response to pivotable movement of said armature, said one depending leg cooperating with said tongue for assisting in maintaining said pawl structure pivotably mounted on said armature, and the other of the depending legs of said pawl structure extending into said passageway and cooperating therewith for also assisting in maintaining said pawl structure pivotably mounted on said. armature.

8. For use with a relay comprising a pivotable armature having a free end and a pawl structure, having a pair of depending legs at its opposite ends, for rotating a ratchet having a plurality of spaced apart teeth; the improvement comprising an armature having pivot faces at its free end, a tongue projecting from between said faces, a passageway spaced from said pivot faces, a second tongue projecting into said passageway, said passageway having a wide portion adjacent said second tongue and a narrow portion opposite said second tongue, said pawl structure being pivotably mounted on said pivot faces, said pawl structure having one of its depending legs extending from said first tongue and cooperating therewith for assisting in maintaining said pawl structure pivotably mounted on said armature and also for engaging and rotating said ratchet in response to pivotable movement of said armature, the other of the depending legs of said pawl structure extending into the narrow portion of said passageway and cooperating therewith for also assisting in maintaining said pawl structure pivotably mounted on said armature, and a third depending guide leg intermediate said pair of depending legs, said third depending guide leg extending into the wide portion of said passageway and cooperating with said second tongue for further assisting in maintaining said pawl structure pivotably mounted on said armature.

9. For use with a relay comprising a pivotable armature having a free end and a pawl member, having spaced apart, depending legs, for rotating a ratchet; the improvement comprising an armature having a passageway adjacent its free end, one of the depending legs of said pawl member extending into said passageway and cooperating therewith for assisting in maintaining said pawl member pivotably mounted on said armature, and a tongue projecting from the free end of said armature, the other leg of said pawl member extending from beneath said tongue for engaging and rotating said ratchet in response to pivotable movement of said armature.

10. For use with a relay comprising a pivotable armature having a free end and a pawl, having spaced apart depending legs at its opposite ends, for rotating a ratchet; the improvement comprising an armature having a passageway with a wide end and a narrow end, one of the depending legs of said pawl having a narrow neck portion for engaging the narrow end of said passageway, a

recess in the other of the depending legs of said pawl, a second tongue projecting from the free end of said armature and extending into said recess and cooperating therewith for assisting in maintaining said pawl pivotably mounted on said armature, and said pawl having a third depending leg intermediate said first two depending legs, said third depending leg extending into the Wide end of said passageway and cooperating with said first tongue for assisting in maintaining said pawl pivotably mounted on said armature.

11. For use with a relay comprising a pivotable armature having a free end and a pawl structure, having a base portion and two depending legs at opposite ends of said base portion, for rotating a ratchet; the improvement comprising a pawl pivotably mounted on said armature and having a third depending leg extending from said base portion and intermediate said first and second depending legs, said three depending legs cooperating with said armature for maintaining said pawl structure pivotably mounted on said armature.

12. For use with a relay comprising a pivotable armature having a free end and a pawl member, having a pair of depending legs at opposite ends, for rotating a ratchet having a plurality of spaced apart teeth; the improvement comprising an armature having a pair of pivot faces at its free end, a tongue projecting from between said faces, a passageway spaced from said pivot faces and aligned with said tongue, said pawl member being pivotably mounted on said pivot faces, one of said depending legs extending from beneath said tongue for engaging and rotating said ratchet in response to pivotable movement of said armature, the other leg of said pawl member extending into said passageway and cooperating with said armature for assisting in maintaining said pawl member pivotably mounted on said armature, and a flat spring member mounted on said armature and positioned between said pawl member and said armature for biasing said pawl member in one direction about its pivotable mounting on said armature, said flat spring member being arranged for allowing said pawl member to pivot in another direction in response to said pawl member engaging and rotating said ratchet.

13. For use with a relay comprising a pivotable armature having a free end and a pawl member, having a pair of depending legs at opposite ends, for providing stepby-step rotation of a ratchet; the improvement comprising an armature having a pair of pivot faces at its free end, a tongue projecting from between said faces, a passageway spaced from said faces and aligned with said tongue, said pawl member being pivotably mounted on said pivot faces, one of the depending legs of said pawl member extending from beneath said tongue for engaging and rotating said ratchet in response to pivotable movement of said armature, and the other of said depending legs extending into said passageway and cooperating with said armature for assisting in maintaining said pawl member pivotably mounted on said armature, and a spring member mounted on said armature for normally biasing said pawl member about said pivot faces and toward engagement with said ratchet.

References Cited in the file of this patent UNITED STATES PATENTS 2,558,953 Henninger July 3, 1951 2,990,723 Holpuch July 4, 1961 3,022,399 Bouer Feb. 20, 1962 3,076,073 Townsend Jan. 29, 1963 3,095,751 Enslein July 2, 1963 3,106,849 Volleov Oct. 15, 1963 

1. AN IMPROVEMENT FOR BIASING A UNITARY PAWL AND DETENT MEMBER WHICH IS PIVOTALLY CARRIED BY AN ARMATURE, SAID IMPROVEMENT COMPRISING A FLAT SPRING HAVING AN LSHAPED DEPENDING LEG AT ONE END AND A PAIR OF LEGS PROJECTING FROM THE OTHER END, SAID PAIR OF LEGS BEING POSITIONED BETWEEN SAID UNITARY PAWL AND DETENT MEMBER AND SAID ARMATURE, AND SAID FLAT SPRING BEING ADAPTED TO BIAS SAID PAWL AND DETENT MEMBER IN ONE DIRECTION ABOUT ITS PIVOTAL MOUNTING ON SAID ARMATURE, SAID ARMATURE HAVING AN OPENING FOR RECEIVING SAID L-SHAPED LEG WITH ONE ARM OF SAID L-SHAPED DEPENDING LEG BEING ADAPTED TO ENGAGE THE LOWER SURFACE OF SAID ARMATURE, SAID ARMATURE HAVING A STOP ELEMENT PROJECTING INTO SAID OPENING, AND A SPLIT PORTION ON SAID SPRING ADAPTED TO ENGAGE SAID STOP ELEMENT UPON DEPRESSION OF SAID SPLIT PORTION, WHEREBY SAID SPRING IS HELD IN PLACE ON SAID ARMATURE BY SAID LSHAPED DEPENDING LEG ENGAGING SAID ARMATURE AND BY SAID SPLIT PORTION ENGAGING SAID STOP ELEMENT. 